Tuesday, January 3, 2017

Phylogenetics versus historical linguistics

Google Trends looks at recent trends in web searches, and it has been used to study patterns in web activity for many concepts. This is similar to The Ngram Viewer in Google Books (see the post Ngrams and phylogenetics). Google Trends aggregates the number of web searches that have been performed for any given search term (or terms), and it can display the results as a time graph, for any given geographical region. The Trends searches are somewhat restrictive, but they may show us something about the period 2004-2016 (inclusive).

So, I thought that it might be interesting to look at a few expressions of relevance to readers of this blog. The Trends graphs show changes in the relative proportion of searches
for the given term (vertically) through time (horizontally). The
vertical axis is scaled so that 100 is simply the time with the most
popularity as a fraction of the total number of searches (ie. the scale
shows the proportion of searches, with the maximum always shown as 100,
no matter how many searches there were).

As you can see, the term "phylogenetics" has maintained its popularity over "historical linguistics". However, it has decreased in popularity through time much more than has "historical linguistics". Nevertheless, both decreases are very small compared to that for the term "bioinformatics", as discussed in the blog post on Bioinformaticians look at bioinformatics.

It is not necessarily clear to me why many technical terms have decreased in Google searches through time, although there are several possibilities. First, it could be Google itself. The Trends numbers represent search volume for a keyword relative to the total search volume on Google. So, actual search numbers for the technical terms could be increasing while as a fraction of total search volume of the internet they are decreasing, if total Google search volume is increasing.

Alternatively, Business Insider has noted that "search is facing a huge challenge ... consumers are increasingly shifting [from desktop] to mobile. On mobile, consumers say they just don't search as much as they used to because they have apps that cater to their specific needs. They might still perform searches within those apps, but they're not doing as many searches on traditional search engines". Furthermore, "people are discovering content through social media. The top eight social networks drove more than 30% of traffic to sites in 2014".

The extra raggedness in search popularity in the first couple of years of the graph probably reflects inadequacies in the Google Trends dataset in the early years (as discussed by Wikipedia). The same is true for the next graph, as well.

The "phylogenetic tree" searches have been more popular than "evolutionary tree", just as was true for the Google Books usage discussed in the post Ngrams and phylogenetics. However, the "phylogenetic tree" searches show a distinctly bimodal pattern every year. This presumably reflects teaching semesters — few people search for technical terms out of term time!

Unfortunately, it is not possible to look at the term "phylogenenetic network", because Google Trends tells me that there is "Not enough search volume to show results". How rude!